The plastic kit is made of a rather hard plastic and castings are pretty rough, You have to glue the arm in position. I used quick-setting super glue rather than plastic cement.

The MTC version is brass with just the grids to fit. I hadn't realised that the arm doesn't pivot around the base of the loop but the latter is fixed. There's some nice detail which, I guess, is why it's so expensive.

These should be enough for Ni-Hao - wouldn't like to fund a larger layout!